Rinse the cherry tomatoes and basil leaves, and pat them dry. Drop the tomatoes into a blender jar or food-processor bowl, followed by the basil leaves, garlic clove, the almonds, hot red pepper flakes, and 1/2 teaspoon salt. Blend for a minute or more to a fine puree; scrape down the bowl, and blend again if any large bits or pieces have survived. With the machine still running, pour in the olive oil in a steady stream, emulsifying the puree into a thick pesto. Taste, and adjust seasoning. (If you're going to dress the pasta within a couple of hours, leave the pesto at room temperature. Refrigerate it for longer storage, up to 2 days, but let it return to room temperature before cooking the pasta.)

To cook the spaghetti, heat 6 quarts of water, with 1 tablespoon salt, to the boil in a large pot. Slip in the spaghetti, and cook until al dente.

Scrape all the pesto into a big warm bowl. Lift the cooked spaghetti up, drain briefly, and drop directly into the pesto. Toss quickly to coat the spaghetti, sprinkle the cheese all over, and toss again. Serve immediately in warm bowls.